Circus cars are sometimes just flat cars which carry the animals’ cages. But some of them are specially built like stables, with stalls and a storage place for food. Fancy race horses ride in padded stable cars, too.
A pickle car is made of six separate wooden tanks. Men at the pickle works fill them with cucumbers and brine. Then the car delivers them at the factory to be bottled.
TRESTLES, TUNNELS AND THINGS
Have you ever wondered why some railroad bridges across rivers are so very high, while automobile bridges are quite low? The trains look a little scary, rushing along way up in the air. But there’s a good reason why they do it, and those tall trestles are so wonderfully planned and built that they are very safe.
Trains can’t climb hills nearly as well as automobiles can. The slopes that trains go up must be very gentle ones. Even a little bit of up-and-down grade slows a train a great deal. So the men who build railroads try to make the tracks run along as nearly level as possible. Next time you see a high bridge across a river, look at the rest of the country around. You’ll see that the river cuts deep down between two hills. The bridge is built on tall stilts that make a level path for the train from one hilltop to the other.
When trains have to go up or down a very long hill, the builders have a problem. They must slope the
tracks very gradually. In mountains this means that the tracks zig-zag back and forth, with long, wide curves between the zigs and the zags. If you look back at the picture on [page 19], you will see how one railroad solved the problem. The rails are laid so that they spiral upward, making a loop. When a very long train travels along the loop, it’s like a huge snake coiled around over its own tail!
